import java.util.ArrayDeque;

public class Stack<T> {

	private ArrayDeque<T> deque = new ArrayDeque<T>();

	public void push(T obj){
		deque.push(obj);
	}
	public T pop(){
		return deque.pop();
	}
	public T top(){
		return deque.peek();
	}
	public int size(){
		return deque.size();
	}	
	public boolean isEmpty(){
		return deque.isEmpty();
	}
}
